Q: I have this processor: http://support.packardbell.com/uk/item/index.php?i=spec_6931190200&ppn=PB14207401 Can it be upgraded to Core 2 Duo without replacing the motherboard?
A: The motherboard is based on a 915 Intel chipset - Socket775 with DDR memory. Bad news - 915 chipset doesn't even support old P4 based dual core, never mind core 2. So the absolute max would be a P4 660/661 - even the Pentium D8xx and D9xx are unsuitable. With a 540J (3.2GHz, hyperthreading, XD), any upgrade it could take is probably not worth doing - a 660 would add only an extra 400MHz, and the 2MB cache is slower than the 1MB of the 5 series, so the advantage is questionable.